In France at my mandatory job physicals, generaly it was the doctor, male or female who instructed me to pull down my brief on the reverse of school physicals where it was always the doctor himself, most of the time a lady doctor who pulled herself my brief down by slipping her hands into the waist band of my brief usually as for others without warning or comment.
In high school, it was different because we had a PE teacher very old school who supervised us in the locker room where we undressed as usually in briefs in group and he introduced a new rule which was to remove our brief just when we were the next to be examined and to stand in front of the door of the exam room stark naked.
At job physicals, it was more thorough the first years and usually the doctor told me to drop my underwear. for the last part of the exam.
One of you told that oldest doctors were those who were old school and did not mind to drop themselves the underwears of young patients because they were used to do it. It happened to me wihout any warn at a medical center for a complete check -up.
After these school physicals from 15 to 18 age, I had the experience of mandatory draft physicals at a military re-induction center three times because I was postponed two times for medical reasons but nothing serious. We were stark naked also but I remember well that these draft physicals were very thorough including thorough inspection of genitals, a lot of orthopaedic exercices, a long inspection of the spine, a visual inspection of the anus area and even a digital rectal examination for the first time of my life.